Mr Cray said Mr Mahmood had posed as a wealthy producer staying in Cannes in the south of France for the world-renowned film festival.

The undercover reporter had gained Contostavlos's trust, Mr Cray said, and in one phone call played to the court she spoke to him about breaking up with her boyfriend, a footballer, whom she described as an "a**ehole".

Mr Mahmood met the singer in Las Vegas while she was in America trying to boost her acting career, and dined with her at Nobu, the popular celebrity hangout, in London, the court heard.

While at the Metropolitan Hotel with Mr Mahmood on May 10 last year, the singer spoke about being able to get "white sweets" - slang for cocaine - and "green sweets" for cannabis, it is alleged.

In a conversation on May 21 she spoke to Mr Mahmood again and promised him "white sweets" for a boys' night out at an east London strip club run by her ex-boyfriend, Adam Bailey, jurors heard.

The court was played the phone call in which the reporter said: "What about white sweets?", and Contostavlos replied: "Yes, definitely on the day.